service upgrade advice - addition

Trying to determine if I should upgrade service from 100 to 200A for my upcoming addition.

House is currently 1100 sq ft. Addition to be between 700-850 sq ft. 2 bdrms and one bath. possibly a "bonus" room as well. House currently has 100A service, we rarely ever trip a breaker.

Currently, my oven/stove/dryer are all propane. Hot water is indirect off oil fired boiler. My bigger electric draws are my fridge, microwave, an extra freezer, pool pump, and potentially a sump pump, but that thing has been bone dry for over a year (knock on wood) I run 3 window ACs in the summer, about 24000 BTU total.

Local official said I shouldn't need to update electric if i have two empty breakers on the panel (I do). However, my panel is an older pushmatic. In looking into requirements, it seems recent code could require AFCI outlets in the new bedrooms, and I don't think my panel is capable of that.

I have a newer sub-panel in my garage which is a GE, and that may be capable of AFCI, but there's only one open breaker currently.

I'm also adding ductwork for central AC (heat is baseboard hotwater) while the floors/walls open, so central AC will be installed at some point instead of the window units.

trying to decide whether I should just bite the bullet and have my service upgraded to 200A with a nice new panel now, so when we start the renovation there are no surprises (still in early phase with architect), or wait, and have it be part of the whole renovation once we get going....Or, roll the dice on 100A being enough, and the AFCI issue not coming to fruition (probably unlikely), or wiring bedrooms from the empty on sub-panel assuming it can handle AFCI, and bathroom from one of the emty breakers on the main.

I also have a wife and three girls. Girls are age 5 and under now....but at some point in the future, there could be a "perfect storm" situation of 4 hairdryers going all at once :-)